In heliarc and similar types of welding, it is common to use what the industry calls "exotic metal" welding wire which not only is comparatively expensive, but also is usually marketed in relatively short lengths rather than in a coil such as is conventional practice with relatively low cost welding wire. For example, Stellite welding wire is normally marketed only in 12-inch lengths and at a cost of the order of $40 per pound, and welding wire containing titanium is normally sold only in 20-inch lengths at a cost of the order of $100 per pound. Even less expensive stainless steel welding wire is usually marketed only in lengths of 20-24 inches, at a cost in the range of $15-$20 per pound.
There is a practical limit to the extent to which a single piece of welding wire can be used before it becomes too short for safe handling at the temperatures to which it is heated during welding. For example, the usual practical limit is of the order of 3 inches. Any shorter piece can be used only if the welder adopts the cumbersome procedure of holding the stub wire with a pair of pliers, but that is not practically possible for a piece shorter than 2 inches, because of the excessive heat problem. Thus with welding wires of the materials and costs outlined above, the unusable portion of each piece may constitute as much as from 10% to 25% of the original length, and this necessarily means the loss of the corresponding percentage of the original cost of the wire.
The desirability of attempting to reduce or eliminate this built-in loss of welding wire and money has been recognized in the past, but to the extent of the knowledge of the present inventor, no satisfactory solution has been proposed or found. For example, it has been a usual practice for welding shops to collect the stub pieces of welding wire which were too short to use until a substantial number had been accumulated, and then to weld them in end-to-end relation into a single longer piece. However, the present inventor knows of no satisfactory technique or equipment, prior to the present invention, for carrying out such an operation.
More specifically, if the operation is attempted by arranging two pieces of welding wire on a welding table and then welding them together, it is difficult and cumbersome to hold the wire pieces in aligned and abutting relation, and the result will commonly be a relatively zig-zag length of wire which includes misshapen and/or over-sized weld joints. Further, this technique is so time-consuming that the labor cost would substantially reduce, or even fully offset, the savings represented by the value of the reclaimed pieces as compared with the cost of new full length wire pieces.